Electric alarm and indicating device



Oct. 21, 1947. J. A. M LAREN 2,429,363

. ELECTRIC ALARM AND INDICATING DEVICE Filed Oct. 6, 1945 INVENTOR.

'- 84 JOHN A MGLAQEN BY I I 86 1| mb/ew ATTORNEY Patented Oct. 21, 1947UNITED STATES PATENT OFFICE 2,429,363 ELECTRIC ALARM A INDICATING DEVICEJohn A. McLare'm Los Angeles, Calif. Application October 6, 1945, SerialNo. 620,800

3 Claims.

This invention relates generally to the art of signals and indicators,and more particularly to devices adapted to warn of a -.predeterminedcondition existing at a location remote from the device.

It is an object of this invention to provide a combined alarm andindicator particularly adapted, although not necessarily, forassociation with a refrigeration or an air conditioning system, to givean audibleand visual signal at a convenient location such as thekitchen, should the correct operating temperature of the system fail tobe maintained by a remotely located refrigeration or air conditioningunit, so that a sufficiently advance warning will be given to preventloss or inconvenience should the unit not be functioning properly;should the current supply fail either temporarily, or by a burned outfuse, or by inadvertent or accidental removal of the electric plug fromthe source of current supply.

It is another object of this invention to provide an alarm andindicating system or device of the above described character which iscompcsed of a simple, rugged and relatively inexpensive structure ofneat and attractive appearance, Whose parts positively co-act to give adual warning in the event of improper functioning of the system which itis operatively connected with remotely, by sounding an alarm andrendering a visual indicatoractive for observation at any time, so thatshould the alarm be sounded when no one is in attendance, and ceasesbefore anyone is in hearing distance, the visual indication will remainas a constant warning, all to theend of affording maximum protection tothe owner against loss or inconvenience incident to failure of therefrigeration or air conditioning system to function properly,

With these and other objects in View, the invention resides in-thecombinations and arrangements of elements as set forth in the followingspecification and particularly pointed out in the appended claims.

In the accompanying drawing,

Figure-1 is a vertical longitudinal sectional view of one form of alarmand indicating device embodying-this invention;

Figure 2 is a horizontal sectional view taken on the line 2--2 of Figure1;

Figure 3 is a fragmentary view similar to Figure 1, and illustrating asecond form of alarm and indicating device embodying this invention;

Figure 4 is a fragmentary view in front elevation of a third form ofalarm 'and indicating device embodying this invention;

Figure 5 is a fragmentary View similar to Figure 1, and illustrating afourth form of alarm and indicating device embodying this invention; and

Figure '6 is a View in front elevation partly '2 broken away, of theform of the invention shown in Figure 5.

Ref ng pec icall to th drawing and particularly to Figures 1 and 2, thisform of the invention is compqsedof a streamlined case C of sheet metalwhich incl des a rectangular back or supporting plate l having top andbottom flanges J l a 2 a d a em a e r m cover ie en ed to be secured tothe back plate l 0 by suitable l 14 on h lat ce v n c w 011 h cover.

it n the asin C is a a arm de c and an indicating element I operativelyassociated therewith. alarm device may comprise a conventional form ofelectricbell or buzzer whose base is secured to the plate ill by bolts2|, and supports the usual stationary electromagnet 2;, a vibratingarmature 23 mounted on the base 20 by a spring 24 andhav ng a clapper 25disposed to strike the bell -25. Current for operating the bell may besupplied by a local battery of 6 volts provided by threeseries-connected dry cells 21 supported in a row on the bottom flange l2of the case at one end of the latter, and confined against displacementby a partition gs. This bell circuit includes conductors 29 and 30 withwhich the cells 21 and the bell are in series, are connected to terminalsockets 3,l and 32 mounted on the bottom flange 12. Jacks 33 and 34 areadapted to be plugged into these sockets and are carried by conductors35 and 36 which lead to a remote location at which the refrigeration,air conditioning or other apparatus which incorrect operation is to bewarned against.

The conductors 35 and 30 are connected to contactsS-l and 38 of aconventionalthermostatic or pressure controlled switch S located at theunit so as to directly subject-to variations in the temperature orpressure in the unit as the case maybe. This switch includes a diaphragm;3 9 carrying a bridging contact All for the contacts 3'5 and 30, and isadapted to respond to a predetermined dangerous temperature rise inthecold c ambe o a r fr g at n uni b e pand n a gas in the thermostatictube 4 of the switch S sufficiently ;for the contact .40 to close-thenormally open bell-oi cuit so as to ring tht bell 2$ and thussound analarm to warn of the incorrect operation of the unit.

"Ifhe indicating element 1 comprises a lighte h a m h n a u t b Wa ninndi ia suchas t w Dan e heme whi ar i p otal -m m a ol fixe ax 9 1521plate 1 -a i en ihe al rmfl wh and n c qse roximity to the endof thecase C. The case is provided with an openingin the form of a slot 52disposed to .freely pass the arm during movement thereof ,from its.nonesignaling .con- .ce'aled position within the case as shown in iulllines in Figure ,1, to .its signaling ,position wherein arm and amovable part of the bell, in the present instance the armature 23 towhich the other at 55. In its nor mal non-signaling position, the arm 50is tilted end of the cord 54 is connected slightly from theperpendicular in a direction to gravitate inwardly of the case, andis'maintained traction of the armature by closing of the bell circuit,whereby the element 82 wil1 be free to be moved by the spring 84 to itssignaling position.

It will be manifest that in all forms of the invention, the activationof the audible signal will cause a visual indication to be given andmain- ;tained for observation at any time. It will be in that positionby the cord 54' which is pulled,

taut under this gravitating action of the arm, as shown in full lines inFigure 1.

However, upon closing of the bell circuit at the contacts 3'! and 38,the initial attraction of the armature 23 by the electromagnet 22, jerksthe cord with sufiicient force to tilt the arm 50 in a directionoutwardly of the case, so that the arm positively gravitates to itssignaling position shown in broken lines in Figure 1. With the arm 50 insignaling position, the distance between the points of connection 53 and55 of the cord 54 to the arm and armature, respectively, has beenshortened suificiently for the cord to be slack as shown in broken linesin this figure, and thus enable free and unrestricted ringing of thebell to be efiected.

It will be clear that should there be no one in attendance at the deviceor in hearing distance of the bell during the period it is ringing untilthe battery cells become exhausted, the arm will provide a constant andpermanent indication for observation at any time later, thus providingfurther assurance that the warning given by the device will be noticed.

In the form of the device shown in Figure 3, there is substituted forthe flexible connection 54 a lug 68 on the bell armature 23a whichco-acts with alug 6| on the indicating arm 50a to normally retain thelatter in the slightly outwardly tilted non-signaling position shown infull lines, against the action of gravity tending to swing the armdownwardly and outwardly of the case Cl through the slot 52a to thesignaling position shownin broken lines. Thus, completion of the bellcircuit will disengage the lug 63 from the lug 6| upon initialattraction of the armature 23a by the electromagnet, to render the arm56a free to gravitate to signaling position.

In the form of the invention shown in Figure which may include either ofthe above described operating mechanisms for the signal arm, the case C2is provided with a window 78 suitably located to expose the arm 50b toview within the case when the arm has moved to its signaling position,thus confining all moving parts in the case.

In the form of the invention shown in Figures 5 and 6, the warningindicia 88 such as the word Danger can be applied to a convenientlyvisible wall 8| of the case C3 and can be normally covered by a shieldelement 82 pivoted on the case at 83 and urged by a suitable hingespring 84 to the lowered position shown in broken lines in Figure 5, toexpose the warning indicia to view.

A spring-pressed latching pin 85 mounted in the case C3, normallyco-acts with a keeper 86 on the element 82 to latch the latter up in thenon-signaling position shown in full lines in Figure 5. A cord 8! orother flexible operative connection is trained over a pulley 88 in thecase, and is connected to the latch pin 85 and to the bell armature 23bso as to release the latching pin from the keeper 86 in response toinitial atnoted from Figure 1 that if it is desired, a push buttonswitch 90 for testing the bell circuit can be mounted on the case 0 andconnected across the conductors 29 and 30 so as to complete the bellcircuit when the button is pushed.

I claim:

1. An alarm and indicating device comprising: an audible signalincluding an electromagnet and an armature vibrated thereby in responseto the supply of current to the electromagnet; an indicating armpivotally mounted about a fixed axis and normally gravitating in onedirection to a non-signaling position; and a flexible connection betweensaid arm and said armature, operable in response to initial attractionof the latter by the electromagnet when energized, to exert a pull uponsaid arm sufficient for the arm to gravitate in the other direction to asignaling position.

2. An alarm and indicating device comprising: an audible signalincluding an electromagnet and an armature vibrated thereby in responseto the supplying of current to the electromagnet; an indicating armpivotally mounted about a fixed axis and normally gravitating in onedirection to a non-signaling position; and a flexible connection betweensaid arm and said armature, operable in response to initial attractionof the latter by the electromagnet when energized, to exert a pull uponsaid arm suflicient for the arm to gravitate in the other direction to asignaling position; said flexible connection being drawn taut by saidarm when gravitating to non-signaling position, so as to act indetermining such position of the arm; said flexible connection beingslack when said arm occupies signaling position so as to render saidarmature free to continue vibrating.

3. An alarm and indicating device comprising: a case having a verticalslot in an exterior wall thereof; an alarm device in the case includingan electromagnet and an armature vibrated thereby when current issupplied to the electromagnet; an indicating arm pivoted about ahorizontal axis adjacent said slot to mount the arm for movement from anon-signaling position in the case to a signaling position wherein thearm projects from the case through said slot; and a flexible memberconnected to said arm and to said armature to normally be pulled taut bythe arm in tending to gravitate to non-signaling position; said memberbeing responsive to movement of the armature by the electromagnet whenenergized, to jerk the arm suificiently for the latter to reverselygravitate to signaling position, with said member being slack followingsuch operation thereof, so as to render the armature free for vibrationas aforestated.

J. A. McLAREN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

